Means for securing an annular shaped winding in a magnetic body



June 7, 1960 K. STEINHAUSER 2,940,019

MEANS FOR SECURING AN ANNULAR SHAPED INDING IN A MAGNETIC BODY Filed Feb. 1, 1957 l J35. lju

i IN VEN TOR.

United States Patent MEANS FOR SECURING AN ANNULAR SHAPED WINDING IN A MAGNETIC BODY Kurt Steinhauser, Ziegelstrasse 17, Ravensburg, Germany Filed Feb. 1, 1957, Ser. No. 637,678

4 Claims. (Cl. 317-158) This invention relates to means for securing annular shaped windings in magnetic bodies which are subjected to severe stresses and is specifically directed to a method for securing the exciting winding of an electromagnetic clutch in its magnetic body.

Electromagnetic clutches of the type to which this invention is directed are set forth in the United States patents to Ryba Nos. 2,254,625 and 2,344,111 as well as in copending application Serial No. 548,801, filed November 25, 1955, entitled -Electromagnetic Clutch with Stationary Coil, to Diebold and assigned to the assignee of the instant invention.

During operation, of an electromagnetic clutch ex- A tremely high forces in both the axial and peripheral directions are imparted to the magnetic body containing the energizing winding for the clutch. That is to say,

when the clutch is engaged and disengaged, the winding I and the magnetic body within which it is situated is subjected to extremely high accelerations and decelerations respectively which result in forces that attempt to move the energizing winding with respect to the magnetic body with which it is maintained.

Furthermore, the energizing winding which is normally comprised of copper or aluminum wire is subjected to relatively high temperature fluctuations during operation thereof so that the winding is subjected to expansions and contractions of a different degree than the 1 magnetic housing within which it is situated in view of the different thermal expansion of the magnetic body.

' Hence the sealing method utilized in sealing the energizing winding within its cooperating magnetic body must be capable of withstanding forces due to thermal contraction and expansion as well as those due to acceleration of the magnetic body during operation of the clutch.

In the past, it has been the practice to roughen the interior walls of the annular shaped opening in 'a magnetic body which received the exciting winding whereby a sealing compound may be introduced in an attempt to rigidly adhere the sealing body to the roughened walls of the magnet so as to positively maintain the exciter winding in position. It has been found, however, that this type of fastening method has failed after relatively short periods of operation.

The principle of this invention is to provide one or more grooves within the walls of the annular shaped opening in the magnetic body which receives the exciter winding wherein the grooves may weave into and out of a plane which is perpendicular to the axis of the magnetic body. The cross-section of the grooves may have any desired shape such as a rectangular or triangular shape and they provide a positive seat for a sealing compound which is to fasten the exciter winding with respect to the magnetic body.

Since the general direction of the grooves runs around the periphery of the annular shaped opening of the mag netic body, it is clear that axial thrust of the exciting winding with respect to the magnetic body will be positively prevented and in a similar manner since the grooves weave into and out of a'plane perpendicular to the axis of the magnet body, peripheral thrust or axial rotation of the winding with respect to the magnet body is prevented.

Moreover, this novel invention provides advantages with regard to manufacture of the magnet body since a simple grooving operation on the magnetic body is all that is required rather than a more complex operation wherein the surface of the annular opening in the magnet body is roughened.

It is, of course, also possible to utilize any desired number of radially extending grooves in the end wall of the annular shaped opening of the magnet body so as to further increase the resistance to torsional stresses set up between the magnetic body and the energizing winding.

Accordingly, a primary object of this invention is to provide a novel method for maintaining an annular shaped energizing winding in position with respect to an annular shaped opening in a magnetic body.

Another object of this invention is to groove the inner annular surfaces of a magnetic body annular shaped opening which receives an exciting winding wherein the grooves provide means for rigidly anchoring sealing compounds which seal the exciting winding within the magnetic body annular shaped opening. I

A still further object of this invention is to provide grooves in both the inner and outer surfaces of an annular shaped opening of a magnet body which weave into and out of a plane which is perpendicular to the axis of the magnet body wherein an annular shaped winding may be rigidly sealed in position with respect to the magnet body.

Still another object of this invention is to provide a novel method for securing an energizing Winding in an annular shaped opening of a magnetic body wherein the end wall of the magnet body contains radially extending grooves for receiving a sealing means so as to provide resistance against torsional stress introduced between the magnet body and the exciting Winding.

These and other objects of this invention will become apparent from the following description when taken in connection with the drawings in which:

Figure 1 shows a cross sectional view of a magnet body containing an annular energizing winding. Figure 2 is a view of Figure 1 taken across the lines 2.2. a

Figure 3 is a cross sectional view similar to Figure l, and particularly shows the novel groove means of this invention as applied to the inner and outer annular walls of the magnet body.

Figure 4 shows a second Figure 5 shows a still invention.

Figure 6 schematically illustrates the annular groove of Figure 5 when expanded in a two-dimensional plane.

Figures 1 and 2 show a magnet body 10 which could be the magnet body utilized in US. Patent No. 2,254,625 to Ryba which is here made part of the instant application. However, the magnet body 10 could be a magnet body for any application wherein it is subjected to severe axial or torsional stresses. The magnet body 10 contains an annular shaped opening 11 within which energizing coil 12 is positioned.

In order to prevent either axial or rotational movement of coil 12 with respect to magnet body 10, a sealing compound 13 is injected into annular recess 11 and binds the coil 12 to the magnet body 10. In accordance with this invention, the upper radial wall of the annular shaped opening 11 is provided with grooves '14 and 15 while the inner radial wall is provided with grooves '16 and 17. These grooves may be best seen in Figure 3 wherein the portion of the figure above the center line shows the embodiment of this invention. further embodiment of the grooves and 15 as interweaving into and out of a plane which is perpendicular to the axis of the magnet body 10.

In a similar manner the grooves 16 and 17 on the inner wall of the annular shaped opening 11 are seen in Figure 3 below the center line of magnet body 12, these grooves also interweaving into and out of the: above mentioned perpendicular plane. v v

Therefore, the mere presence of the grooves which are in a general peripheral direction will prevent axial motion of the exciting winding 12 of Figure I and the sealing compound 13 with regard to the magnet body 10, while the interweaving of the grooves will prevent an axial motion of the winding 12 with respect to magnet body *10. That is to say, the grooves will provide a positive anchor for the sealing means.

' In order to further enhance the limitation of'the axial motion, the end. wall of the annular groove 11 may, as is shown in- Figure 2, be provided with radially extending grooves" which rigidly grasp the sealing compound and prevent an axial rotation of the energizing winding 12.

' Figure 4- shows a second embodiment of this invention which is substantially identical to that of Figure 3 and differs therefrom only in the crossing of grooves 16 and 17 in the outer annular wall of groove 1-1 of Figure 1 while grooves 18 and 19 which are in the inner annular wall of annular opening 1 1 cross in a similar manner. This type of structure may be desired to afford a more positive gripping of the sealing compound for the prevention of axial-motion of the energizing winding 12 with respect to the magnetic body :10.

A still further extension ofthis novel invention is set forth in Figure which shows a side cross sectional view of a magnet body 20 (as well as a ring collector 21 which cooperates with a brush for energizing a winding) having an annular shaped opening 22. Five interweaving grooves '23, 24-, 25, 26 and 27 are then placed in the outer annular wall of opening 22, these grooves interweaving with one another in the manner shown in Figure 6-which shows the outer wall on a linear scale.

In a similar manner, the inner wall of groove 22 may contain a similar arrangement of interweaving notches 28, 2'9, 30, 31 and 32. This arrangement, set forth in Figures 5 and 6, is particularly well adaptedfor the prevention of either axial or rotational movement of the coil. positioned within groove 22 and fastened therein by means of a sealing compound and the magnet body 20.

Although I have here described preferred embodiments of my novel invention, many variations and modifications will now be evident to those skilled in theart and I prefer therefore to be limited not by the specific disclosure herein, but only by the appended claims.

What is claimed is:

1.- In a magnetic body having an annular shaped opening therein for receiving a coaxial winding and sealing means for securing said coaxial winding in said annular shaped opening; a groove extending around the periphery of one of the surfaces of said annular shaped opening for providing an anchor for said sealing means; said groove interweaving into and out of a plane perpendicular to the axis of said magnetic body for providing anchoring against stress in an axial or peripheral direction.

2. In a magnetic body having an annular shaped opening therein for receiving a coaxial winding and sealing means for securing. said coaxial winding in said annular shaped opening; a groove extending around the periphery of one of the surfaces of said annular shaped opening for providing an anchor for said sealing means; and radially extending grooves in the end wall of said annular shaped opening; said peripheral groove providing anchoring against axial stress, said radial grooves providing anchoring against peripheral stress.

3. In a magnetic body having an annular shaped opening therein for receiving a coaxial winding and sealing means for securing said coaxial winding in said annular shaped opening; a plurality of grooves extending around the periphery of one of the surfaces of said annular shaped opening for providing an anchor for said sealing means; said plurality of grooves interweaving into and out of a plane perpendicular to the axis of said magnetic body for providing anchoring against stress in an axial or peripheral direction.

4. In a magnetic body having an annular shaped opening therein for receiving a coaxial winding and sealing means for securing said coaxial winding in said annular shaped opening; a plurality of grooves extending around the periphery of one of the surfaces of said annular shaped opening for providing an anchor for said sealing means; said plurality of grooves interweaving into and out of a plane perpendicular to the axis of said magnetic body for providing anchoring against stress in an axial or peripheral direction; and radially extending grooves in the end wall of said annular shaped opening for providing further anchoring against peripheral stress.

References Cited inthe file of this patent UNITED STATES PATENTS 2,240,866 Smith May 6, 1941 2,439,230 Weyandt et 'al Apr. 6, 1948 

